Metal skimming ladle



. J. E. WEILER 2,431,288

METAL SKIMMING LADLE Nov. 18, 1947.

2 Sheets-Shet 1 Filed Oct. 28, 1942 INQE NT R John 5 14422627 ATTORNEYS Patented Nov. 18, 1947 M=ET-A-L SKIMMING more John E. Weiler, Lake Cha le ass emr its.

he a s n Alkali Wo ks, 1 0-, N w XQrk,

' Y,., La corpntation of Virginia Application October '28, 1942, Serial No.463g577 LClaim. .1

his in niiqn re ate to the p oduction o l g m t 1 .:sa sf ions and has t our its hi the P is on o an im oved ladle for emoving h o en f om he p a e where itispfi l 1 d1QI c l ected andsenaratine-it from the ed a tthe h ot u tier 01 15 11; metal, t r e mp e y the .elec rel sis h fuse sa the metal is usually collected in a Well wherein it floats on thef'used salt. Elli-11s invention .:pr o vid es n v d lad-1e f remo in th m ta rom the fused salt with less effort and with less loss of metal.

While the l d is use u io re ov n n l ht metal, that is any metal lighter than the fused salt, from fused salt, whether the metal is produced by chemical reduotion or ,by electrolysis, it is especially advantageous the removal and separation of magnesium produced by electrolysis of'magnesiumchlorid fusions.

In present practices, floating molten mag-nesium is removed frpm the fuse dtsalt, from whichit is produced by electrolysis tor example, .by skiinming with avsmall iron ladle. One form 2of ladle for removing the magnesium has a number of small holes in :the hottom for effecting a selective separation of the r et salt from the magnesium. The operator scoops a ladle full of magnesium and salt and raises it above the surface of the salt, allowing the fused salt to drain through the sn all holes. Since the molten magnesium does not wet the iron, very little magnesium drains through the holes if they are small enough. When the ladle is thus emptied of fused salt, it is again immersed "and the fused salt is again drained off, leaving more magnesium. This operation is repeated until sufficient ma nesium is collected in .the ladle to pour into a ca t n ..mo .d- This removal involve a im consuming and laborious operation and his "ineflicient in that substantial quantities ,Qf maenesium initially separated (escape from the "ladle before pouring.

This, i e t on p ov d a adle wh c m nates the af ementione difiw ties with a r sulting increase in efilgiency'manitestedbyasave 3 ns i me, labo and .ineta removed. The impr e la l of th in ent en vcolrlp ses a eepta e fp receiving metal and fused salt by kimming an ,numplmeans for withdrawin the s d s lt f om the rec tac e, permitti qhe metal to fill :the receptacle. lln a ladle embodyins my invention, it provide a receptacle and a pump in the form ,of la gasrl-ift comprising an upright .duct adjacent the receptacle which communicates through .a small aperture with a bot.- tom portion of the receptacle and .a puzzle for injectin gas into the fused salt in the duct for pumping the fused salt from the bottom of the meceptacle as the metal and fused salt flow .into the receptacle dnring the immersion of the ladle. 'llhe gas for {the gasdifit, nitrogen for example, may conveniently be supplied by running a small rpipe alon the handle of the iladle, into the .receptacle and positioning thenozzle in the bottom of theiduct.

In ane adaptation {of the invention, the wallsof the receptacle extend above the discharge outlet of the duct, permitting the operator to immerse the :ladle the :fusedssalt and metal until the fused salt and metal iflQW rover the :upper edges of the walls :while the discharge outlet is submerged gbelow :the surface of the fused bath. By operating (the tease-"lift, :the fused salt is forced up through the duct and through the discharge outlet. .Wzhen metal sbegins ato .flow out ,of :the'

discharge outlet, :the receptacle is full .of metal.

-In an especially ;adv.antageous form of ladle embodyin the invention, :1 provide .a receptacle having aupper walls arranged to extend above the surface of the fused .salt when the ladle is immersed for the skimming ;operation, an inlet opening on one side just :below the surface and a duct for the igasrlift, preferably along an opnosite side of :the receptacle, the discharge outlet of which-is also below the'surface. This form .of ladle is preferably used by immersing it :in the mixture of metal and fused salt sufliciently to Submergethe inlet opening and discharge outlet while leaving the upper .edges of the receptacle wal s ab ve he surfac :In another adapt of the invention,;I proMide tapouring spout opening into the receptacle :near its bottom to facilitatepour-ing {of anylfused s alt remaining from the ladle before pouring the collected metal into a ca t mold.

These and othennotelfeatures of the invention will be further described in connection with the ac ompa d aw nesin whic i t a s de riew f om abov with par w h i slede embodyin th i te t on;

Fig. 2 is an elevation, partly in section, of another form of ladle embodying the invention,

Fig. 3 is a plan of the ladle illustrated in Fig. 2,

Figs. 4 and 5 are, respectively, an elevation, partly in section and a plan of another form of ladle embodying the invention, and

Figs. 6 and 7 are similar views of still another form of ladle embodying the invention.

The ladle illustrated in Fig. 1 comprises a cylindrical wall I having an outwardly flared upper edge 2 and a bottom 3 forming a receptacle 3. Along one side of the cylindrical side wall, an upright duct 5 is provided, as by welding a U- shaped plate 6 to the wall. The duct has a discharge opening I which is at an appreciably lower level than the edge 2 and an aperture 8 in the wall I provides a communicating passageway be- '1 tween the duct and the receptacle. At a position approximately at right anglesto the duct 5,-a handle 9 is attached to the wall I. The nozzle ll) for the gas-lift is located in the lower portion of the duct 5, and as a convenient means of supplying the nozzle with gas, a small pipe I I is extended 1, along the handle, into the receptacle, and through the opening 8 where it terminates in the nozzle I 9.. The endof the pipe I I connects to a valve I2 which is connected to a hose l3 leading to a source of inert gas such as nitrogen. In using the ladle of Fig. l in the removal of magnesium from the well of an electrolytic cell containing magnesium and a fused salt electrolyte, the ladle is immersed in the well to a point where the edge 2 is just beneath the surface. In this skimming operation, the magnesium floating on the surface of the electrolyte, together with some electrolyte, flows into the receptacle 4. The electrolyte settles to the bottom and, when valve I2 is opened, nitrogen is injected through the nozzle I 0, withdrawing the electrolyte through the opening 8 and forcing it up through the duct 5, through the discharge outlet 1 back into the electrolyte in the well. When the gas-lift begins to discharge metal through the outlet 1, the valve I2 is shut oif and the ladle full of metal is removed from the well for pouring into a mold. I .The ladle illustrated in Figs. 2 and 3 is rectangular in cross-section comprising sides 26 and 2|, ends 22 and 23, and a flat bottom 24. As shown in Fig. 2,.the upper edge of the end 22, sides 20 and 2I and partition 21 extend above the upper boundaries of the inlet opening 29 and the discharge opening 35 and above the normal metalfused salt level 26 when the ladle is immersed. The upper edge of wall 23 and the upper edges of the laterally extended parts of walls 20 and 2| terminate at 29 forming a rectangular inlet opening 30.. The relatively small U-shaped member 32 attached to the wall 22 forms an upright duct 33 closed at its lower end which communicates with the bottom of the receptacle through the opening 34 in the wall 22. The nozzle 36 for the gas discharge is at the end of the small pipe 3! which extends along the wall' 22 in the'receptacle and through the opening 34. The handle 38 for the ladle is attached to the wall 22 and the pipe 31 is preferably extended along the handle to the valve or gas cock 39. The valve is connected to a hose 40' which leads to a source of nitrogen or other inert gas. In order to facilitate the pouring of metal out of the receptacle, a spout ll is formed on the wall 2! at the upper edge 29.

' By way of example, a ladle of the type illustrated in Figs. 2 and 3 may have the following approximate dimensions in inches: Length along thebottom8; width between Walls 20 and 2 l-Sf diameter of duct 23-l diameter of pipe 36 height of edge 35 and edge 29;6 height of edge 7 electrolytic cell containing magnesium metal and a magnesium chloride fusion, the ladle is immersed in the electrolyte and floating metal as shown in Fig. 2, the metal-electrolyte level being indicatedat 26. This permits the molten magnesium and fused salt electrolyte to flow from the surface of the body into the receptacle 28 through the openings 3il and 35..' Since the edge 25 extends above the level 26, the metal floating on the top of the material collecting in the ladle is prevented from floating away. When the receptacle is filled to the level 25, the valve 39 is opened f and nitrogenis injected through duct 33 at a moderate rate, so as not to create turbulence,

pumping electrolyte from the bottom of the re- .ceptacle through the hole 34 and through the discharge outlet 35. The pumping is continued while magnesium and electrolyte continue to flow into the receptacle through the opening 30. More andmore metal enters the ladle and the metalelectrolyte interface drops until metal is expelled by the gas-lift. Actually there is no sharp interface, but a zone where separation is taking place. -When this zone drops to a level such that metal is expelled by the gas-lift, the ladle is raised somewhat, about two inches, with a ladle dimensioned as above so that no more metal and electrolyte are-drawn in, and pumping is reduced with the ladle tilted toward the duct 33 removing substantially all of the electrolyte which entered the ladle before it was raised. The ladle is then lifted from the well. -By merely tilting the ladle, the metal is poured through spout 4| into any suitg able mold.- Pouring is stopped before any elec-'- trolyte left in the ladle starts to come over the lip. The ladle illustrated in Figs. 4 and 5 corresponds to the ladle illustrated in Figs. 2 and 3, in construction and use, except that one end of the opening 36a is covered with a'plate 42 and a tube 43 is provided opening at one end through the plate 32 and at the'other near the bottom of the receptacle 28a. The tube 43 thus constitutes a pouring spout which, together with plate 42, permits pouring from'the bottomjof the receptacle 28a of any fused salt left in the ladle before pouring the metal into a'mold. 1

The ladle illustrated in Figs. 6 and '7 is similar, in construction and operation, to that illustrated in Figs. 4 and 5." The bottom pouring spout, how ever, is constructed of a U-shaped member 44' attached to the wall 2Ib, closed at its lower end by an extension of thebottom 24b and opening at its lower end into the receptacle 2% through aperture45. In Figs. 4 and 5 and in Figs. 6 and 7, the same reference characters with a and b, respectively; appended designate the same parts designated in Figs.2and3. 1 WW I claim: V An improved ladle for removing. a, light metal from a body of fused salt and metal which comprises a receptacle for receiving metal and fused salt having upper walls arranged to extend above the surface of the body when the ladle is immersed therein, an inlet opening'into the receptacle below the upper edge of said wallsfformetal and fused salt'toflow intothe receptacle from a place near the surface of thesaid b,ody,,and"a gas-liftcomprising an upright duct along one side of the re-" ceptacle opening into the bottom of the receptacle for receiving fused salt and a discharge outlet near the level of the inlet opening for discharging the fused salt pumped out of the bottom of the receptacle.

JOHN E. WEILER.

I REFERENCES CITED Ihe following references are of record in the 1 file of this patent: 

